This invention relates to an improved command bar system which is used in aircraft to indicate pitch and roll information.
Command bars for aircraft serve to convey information to the pilot concerning pitch and roll conditions such as the deviation from a desired altitude. There are two basic types of command bar systems, one of which is known as a double cue system. These double cue systems require a pair of separate meters, one for the pitch mode and one for the roll mode. The pitch meter includes an indicator arm which moves about the pitch axis of the aircraft in a manner to display pitch commands. The roll meter acts similarly to indicate roll commands by means of a meter arm. The information concerning the pitch and roll commands is either displayed visually to the pilot so that he can respond to the indications given by the meters, or it is used in the autopilot mode with the command bars monitering the response of the autopilot. The necessity of providing separate meters for the pitch and roll modes has made existing command bar systems of the double cue type highly complicated and expensive. The cost and complexity is further increased due to the tendency of such meters to incorporate a large number of precision parts, including damping devices, and the like.
The other type of system is known as a single cue system because it indicates both pitch and roll commands with a single meter arm. The conventional single cue command bar is more expensive and complicated even though only a single indicator arm is needed, and has not been satisfactory in all respects. For example, some single cue systems provide complex components such as various types of motors, gears and flex pivots which obviate the economy and complicate the single cue command bar arrangement. Moreover, existing single cue instruments are typically inordinately large and they tend to require large quantities of electrical power, thus greatly adding to their operating expense. Units that utilize electromagnets to displace a magnet typically include several rather large coils which draw inordinate amounts of power. Also, the coils are somewhat distant from the magnet so that the power is not utilized to the full potential in deflecting the magnet.
It is an important object of the present invention to provide a single cue command bar system which is improved in its cost and operational characteristics as compared to existing single cue command bar instruments.
It is another object of the invention to provide a command bar system in which a magnet assembly that carries the indicator bar is mounted to pivot about a pair of edges which correspond to the pitch and roll axes.
A further object of the invention is to provide a command bar system wherein the pitch and roll functions are independent so as not to interfere with or otherwise adversely affect one another.
An additional object of the invention is to provide a command bar system that includes unique bobbins on which coils are wound in a manner to take full advantage of the fields used to deflect the magnet.
Yet another object of the invention is to provide a command bar system in which the magnet is located as close as possible to the coils in order to maximize its deflection with a minimum amount of power. The novel configuration of the bobbins and the arrangement of the coils thereon is important in this respect since the magnet ends are able to extend into the bobbins within the high intensity areas of the fields.
A further object of the invention is to provide a command bar system which operates accurately and reliably with a small number of precision parts.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description of the drawings.